The absolute worst. This company has representatives trolling Home Depot looking for people to sign up for a furnace "tune-up." Do not take this deal.
What they do is come in, try and find something wrong with your furnace and try to sell you a new one, or else pay their exorbitant repair prices. They fleeced me for $320 to swap out my star/run capacitor on a 12-year-old furnace that was functioning just fine. I did some research after the fact and found out the part was, at most, $50. So they charged $270 for literally 10 min of work! In addition to that, they changed $200 to swap out the media on an in-house humidifier. Again, some research afterwards showed the media was $20 -- in fact a whole new humidifier costs $200.
A month and a half later, the furnace breaks. I have them back in just to see what they would do. Turns out the circuit board went bad. I pointed out to the tech my furnace was fine before they touched it.
So to "make it right" they said they would do the circuit board for the "discount" price of $620, plus throw in a $250 repair of my ignition switch, which the tech said was "about to fail," for free. Or they could put my previous invoice of $600 toward a new $4,000 furnace.
That night I did some research. The circuit board was $170 and the switch $40 -- so their "discounted" price was to charge me almost $400 labor for maybe 20 min. work. Instead I bought the circuit from a local retailer and did it myself.
The people at the retailer also asked me to bring in my ignition switch. We tested it at the store -- it worked perfectly fine. No pitting, no cracking. ARS' claimed that white "residue" on the switch meant it was about to go out. That was an absolute lie. Ignition switches, like start/run capacitors I later learned, are like light bulbs -- you don't switch them out until they fail.
Finally, I had a second tech look over my furnace just to be sure ABS didn't cause any additional problems. That tech said the problem was likely the circuit board all along and that the capacitor repair was just a way for them to make a quick buck. Which they did.
DO NOT use these people under any circumstances. Most of all, NEVER make the dumb mistake I made and go with a repair without first doing your homework. If it's not an emergency, get a quote, do some research, then make a decision.
You'll save yourself a lot of money and trouble.